BOSTON — The cost of bringing the MBTA’s trains, stations, tracks and other assets into good working condition has only grown larger with closer scrutiny, rising to $7.3 billion, according to a presentation on Monday.

That is $651 million larger than the $6.7 billion state-of-good-repair backlog Transportation Secretary Stephanie Pollack reported last winter. Pollack’s earlier estimate was more than double the $3.1 billion state of good repair backlog reported by transportation officials in 2009.

“The number has moved significantly because we’ve become more precise,” said Steven Poftak, a member of the MBTA Fiscal and Management Control Board, who has worked on the issue.

The state-of-good-repair program looks at the cost of replacing or repairing equipment and infrastructure to bring it into good working condition. State of good repair reporting has grown larger and more detailed, covering more than 250,000 assets, up from the 95,316 included in the 2009 report.

As the cost of bringing the system into a state of good repair increases, the tension between the goals of improving existing service and expanding service to new areas could heighten. Last week MBTA officials disclosed that Green Line Extension costs could rise from $2 billion to $3 billion unless steps are taken.

“It’s important to have this information at the same time as the board and the Commonwealth are making decisions about the Green Line because another billion dollars at the Green Line is money that isn’t going into the assets we already have, and it’s a balancing act,” Pollack told reporters. She said, “We have to do both and the questions is how you balance.”

Some “major gaps” remain in the repair database, which lacks data on commuter rail infrastructure, such as rail, power and signals, officials said.

“You can’t even begin to make the right choice until you have that information,” Pollack said after the meeting, referring to the costs associated with establishing positive train control on the commuter rail, the Green Line Extension and state of good repair.

Benefitting from more information than a prior report in February, the report released Monday showed differences both positive and negative compared to the older report.

The new report included major decreases in the amount of work needed for power, bridges and signals, while the state of good repair backlog increased for track and vehicles. Track costs increased by $885 million and vehicle costs increased by $737 million at the same time required signal work decreased $579 million and bridge costs decreased $302 million.

While power assets make up a relatively small portion of the repair backlog, Poftak said the power assets are in the worst shape.

Rail dominates the repair backlog. Subway accounts for 44 percent while commuter rail accounts for 43 percent, and bus service is only 9 percent of the repair backlog. The Red, Green and Orange lines are in the greatest need, while the Blue Line has a relatively small state-of-good-repair backlog, according to a presentation given by MBTA Capital Budget Director Thom Duggan.

Managing the repair backlog will be expensive. The state of good repair backlog could be eliminated by 2040 by investing $765 million annually. Annual expenditures of $472 million at today’s dollar value would keep the repair backlog where it is.

This year the state plans to spend $663 million on state-of-good repair and safety projects. If that level of state spending continued, the backlog would be reduced to $2.6 billion by 2040, officials said.

Between September 2014 and August 2015, the state put $554 million toward the MBTA’s state of good repair program. About $228 million was spent on expansion that same year. In prior years, the MBTA failed to follow through on much of its capital budget.